Study Questions Effectiveness of Single Chlamydia Test

Last Updated: April 09, 2010.
A single chlamydia screening does not prevent most cases of pelvic inflammatory disease over 12 months, and most cases that do occur are in women who were negative for chlamydia at baseline, according to a study published online April 8 in BMJ.

Does not prevent most PID cases; may be best for women with chlamydia at baseline

FRIDAY, April 9 (HealthDay News) -- A single chlamydia screening does not prevent most cases of pelvic inflammatory disease over 12 months, and most cases that do occur are in women who were negative for chlamydia at baseline, according to a study published online April 8 in BMJ.

Pippa Oakeshott, M.D., of the University of London, and colleagues recruited 2,529 sexually active female students (mean age, 21 years). The women provided vaginal swabs to screen for chlamydial infection, and then were randomized to either immediate testing and treatment for chlamydia or storage and analysis after a year.

The researchers found that the incidence of pelvic inflammatory disease was 1.3 percent in screened women compared with 1.9 percent in controls. In addition, 9.5 percent of control women who tested positive for chlamydial infection at baseline developed pelvic inflammatory disease over 12 months compared to 1.6 percent of screened women. However, most occurrences of pelvic inflammatory disease (79 percent) occurred in women who tested negative for chlamydial infection at baseline.

"Although some evidence suggests that screening for chlamydia reduces rates of pelvic inflammatory disease, especially in women with chlamydial infection at baseline, the effectiveness of a single chlamydia test in preventing pelvic inflammatory disease over 12 months may have been overestimated," the authors write.